4. Find an equation for each line.

In a random sample of 150 customers of a high-speed Internetprovider, 63 said that their service had been interrupted one ormore

erastovalidia [21]

Answer:

a) The 95% confidence interval would be given by (0.341;0.499)

b) The 99% confidence interval would be given by (0.316;0.524)

c) n=335

d)n=649

Step-by-step explanation:

1) Notation and definitions

$X_{IS}=63$ number of high speed internet users that had been interrupted one or more times in the past month.

$n=150$ random sample taken

$\hat p_{IS}=\frac{63}{150}=0.42$ estimated proportion of high speed internet users that had been interrupted one or more times in the past month.

$p_{IS}$ true population proportion of high speed internet users that had been interrupted one or more times in the past month.

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{\hat p(1-\hat p)}{n}})$

1) Part a

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 95% of confidence, our significance level would be given by $\alpha=1-0.95=0.05$ and $\alpha/2 =0.025$ . And the critical value would be given by:

$t_{\alpha/2}=-1.96, t_{1-\alpha/2}=1.96$

The confidence interval for the mean is given by the following formula:

$\hat p \pm z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$

If we replace the values obtained we got:

$0.42 - 1.96\sqrt{\frac{0.42(1-0.42)}{150}}=0.341$

$0.42 + 1.96\sqrt{\frac{0.42(1-0.42)}{150}}=0.499$

The 95% confidence interval would be given by (0.341;0.499)

2) Part b

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 99% of confidence, our significance level would be given by $\alpha=1-0.99=0.01$ and $\alpha/2 =0.005$ . And the critical value would be given by:

$t_{\alpha/2}=-2.58, t_{1-\alpha/2}=2.58$

The confidence interval for the mean is given by the following formula:

$\hat p \pm z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$

If we replace the values obtained we got:

$0.42 - 2.58\sqrt{\frac{0.42(1-0.42)}{150}}=0.316$

$0.42 + 2.58\sqrt{\frac{0.42(1-0.42)}{150}}=0.524$

The 99% confidence interval would be given by (0.316;0.524)

3) Part c

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

And on this case we have that $ME =\pm 0.05$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

And replacing into equation (b) the values from part a we got:

$n=\frac{0.42(1-0.42)}{(\frac{0.05}{1.96})^2}=374.32$

And rounded up we have that n=335

4) Part d

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

And on this case we have that $ME =\pm 0.05$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

And replacing into equation (b) the values from part a we got:

$n=\frac{0.42(1-0.42)}{(\frac{0.05}{2.58})^2}=648.599$

And rounded up we have that n=649

5 0

3 years ago

What is the answer? Plzz answer fast! I’ll put you in brainliest.

Olenka [21]

Answer:

No they are not equivalent

8 0

3 years ago

Fill in the missing expression

padilas [110]

Answer:

The complete table is:

[ 5a ] + [ a + 3 ] + [ 4a ] = [ 10a + 3 ]

+ + + +

[ 2b ] + [ 4 + a ] + [ -a ] = [ 2b + 4 ]

+ + + +

[ 2a ] + [ a + 1 ] + [ -3a ] = [ 1 ]

= = = =

[ 7a + 2b ] + [ 3a + 8 ] + [ 0 ] = [10a + 2b + 8 ]

Explanation:

You can determine the content of each box by subtraction, running the rows and the columns.

The expressions are:

[ 5a ] + [ ] + [ 4a ] = [ 10a + 3 ]

+ + + +

[ 2b ] + [ 4 + a ] + [ ] = [ ]

+ + + +

[ ] + [ ] + [ -3a ] = [ 1 ]

= = = =

[ ] + [ 3a + 8 ] + [ ] = [10a + 2b + 8 ]

1. First row:

[ 5a ] + [ ] + [ 4a ] = [ 10a + 3 ]

[ ] = [10a+ 3] - [ 4a ] - [ 5a ] = 10a - 4a - 5a + 3 = a + 3

2. Second colum:

[ a + 3 ] + [ 4 + a ] + [ ] = [ 3a + 8 ]

[ ] = [ 3a + 8 ] - [ a + 3 ] - [ 4 + a ] = 3a - a + a + 8 - 4 - 3 = a + 1

So far, you have completed this:

[ 5a ] + [ a + 3 ] + [ 4a ] = [ 10a + 3 ]

+ + + +

[ 2b ] + [ 4 + a ] + [ ] = [ ]

+ + + +

[ ] + [ a + 1 ] + [ -3a ] = [ 1 ]

= = = =

[ ] + [ 3a + 8 ] + [ ] = [10a + 2b + 8 ]

3. Complete the row 3:

[ ] + [ a + 1 ] + [ -3a ] = [ 1 ]

[ ] = [ 1 ] - [ a + 1 ] - [ -3a ] = - a + 3a + 1 - 1 = 2a

So far, you have completed this:

[ 5a ] + [ a + 3 ] + [ 4a ] = [ 10a + 3 ]

+ + + +

[ 2b ] + [ 4 + a ] + [ ] = [ ]

+ + + +

[ 2a ] + [ a + 1 ] + [ -3a ] = [ 1 ]

= = = =

[ ] + [ 3a + 8 ] + [ ] = [10a + 2b + 8 ]

4. Complete the fourth column:

[ 10a + 3 ] + [ ] + [ 1 ] = [10a + 2b + 8 ]

[ ] = 10a + 2b + 8 - 10a - 3 - 1 = 2b + 4

So far, this is the results:

[ 5a ] + [ a + 3 ] + [ 4a ] = [ 10a + 3 ]

+ + + +

[ 2b ] + [ 4 + a ] + [ ] = [ 2b + 4 ]

+ + + +

[ 2a ] + [ a + 1 ] + [ -3a ] = [ 1 ]

= = = =

[ ] + [ 3a + 8 ] + [ ] = [10a + 2b + 8 ]

5. Complete the second row:

[ 2b ] + [ 4 + a ] + [ ] = [ 2b + 4 ]

[ ] = [ 2b + 4 ] - [ 2b ] - [ 4 + a ] = 2b - 2b + 4 - 4 - a = - a

So far:

[ 5a ] + [ a + 3 ] + [ 4a ] = [ 10a + 3 ]

+ + + +

[ 2b ] + [ 4 + a ] + [ -a ] = [ 2b + 4 ]

+ + + +

[ 2a ] + [ a + 1 ] + [ -3a ] = [ 1 ]

= = = =

[ ] + [ 3a + 8 ] + [ ] = [10a + 2b + 8 ]

6. Complete the first colum:

[ 5a ] + [ 2b ] + [2a ] = [ ]

[ ] = [ 7a + 2b ]

So far:

[ 5a ] + [ a + 3 ] + [ 4a ] = [ 10a + 3 ]

+ + + +

[ 2b ] + [ 4 + a ] + [ -a ] = [ 2b + 4 ]

+ + + +

[ 2a ] + [ a + 1 ] + [ -3a ] = [ 1 ]

= = = =

[ 7a + 2b ] + [ 3a + 8 ] + [ ] = [10a + 2b + 8 ]

7. Complete the last row:

[ 7a + 2b ] + [ 3a + 8 ] + [ ] = [10a + 2b + 8 ]

[ ] = [10a + 2b + 8 ] - [ 7a + 2b ] - [ 3a + 8 ] = 0

The complete table is:

[ 5a ] + [ a + 3 ] + [ 4a ] = [ 10a + 3 ]

+ + + +

[ 2b ] + [ 4 + a ] + [ -a ] = [ 2b + 4 ]

+ + + +

[ 2a ] + [ a + 1 ] + [ -3a ] = [ 1 ]

= = = =

[ 7a + 2b ] + [ 3a + 8 ] + [ 0 ] = [10a + 2b + 8 ]

5 0

3 years ago

Review the steps of the proof.

lana [24]

Answer:

steps 2 and 3 must be switched

Step-by-step explanation:

e2020

7 0

3 years ago

Read 2 more answers

10. The probability of buying pizza for dinner is 34% and the probability of buying

kipiarov [429]

Answer:

The probability of eating pizza given that a new car is bought is 0.952

Step-by-step explanation:

This kind of problem can be solved using Baye’s theorem of conditional probability.

Let A be the event of eating pizza( same as buying pizza)

while B is the event of buying a new car

P(A) = 34% = 0.34

P(B) = 15% = 15/100 = 0.15

P(B|A) = 42% = 0.42

P(B|A) = P(BnA)/P(A)

0.42 = P(BnA)/0.34

P(B n A) = 0.34 * 0.42 = 0.1428

Now, we want to calculate P(A|B)

Mathematically;

P(A|B = P(A n B)/P(B)

Kindly know that P(A n B) = P(B n A) = 0.1428

So P(A|B) = 0.1428/0.15

P(A|B) = 0.952

4 0

3 years ago